Method, system, and computer software code for verification of validity of a pressure transducer

ABSTRACT

A method that includes comparing a first brake pressure measured at a first transducer that is part of a braking system on a lead powered unit of a distributed power (DP) system to a second brake pressure measured at a second transducer that is part of a braking system on a remote powered unit of the DP system. The method also includes determining whether the second transducer is functioning within designated operational parameters when the DP system is operating in a DP mode based on comparing the first brake pressure to the second brake pressure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 12/504,028, which was filed on Jul. 16, 2009 (the “'028 Application”). The entire subject matter of the '028 Application is incorporated by reference.

BACKGROUND

The inventive subject matter described herein relates generally to communication systems and, more particularly, to determining whether a reading from a pressure transducer is valid.

Powered systems such as, but not limited to, an off-highway vehicle, marine powered propulsion plant or marine vessel, rail vehicle systems or trains, stationary power plants, agricultural vehicles, and transport vehicles, usually are powered by a power unit, such as but not limited to a engine, such as but not limited to a diesel engine. With respect to rail vehicle systems, the powered system is a locomotive, which may be part of a train that further includes a plurality of rail cars, such as freight cars. Usually more than one locomotive is provided as part of the train, where a grouping of locomotives is referred to as a locomotive “consist.” Locomotives are complex systems with numerous subsystems, with each subsystem being interdependent on other subsystems.

With respect to a train, under operator control, a railroad locomotive supplies motive power (traction) to move the locomotive and a load (e.g., non-powered railcars and their contents), and applies brakes on the locomotive and/or on the non-powered railcars to slow or stop the train. With respect to the locomotive, the motive power is supplied by electric traction motors responsive to an AC or DC power signal generated by the locomotive engine.

A railroad train has three separate brake systems. An air brake system includes a fluid-carrying (typically the fluid includes air) brake pipe that extends a length of the train and a railcar brake system. Wheel brakes are applied or released at each locomotive and at each railcar in response to a fluid pressure in the brake pipe. An operator-controlled brake handle controls the brake pipe pressure, venting the brake pipe to reduce the pressure to signal the locomotives and railcars to apply the brakes, or charging the brake pipe to increase the pressure to signal the locomotive and railcars to release the brakes. For safe train operation, when pressure in the brake pipe falls below a threshold value the brakes default to an applied condition.

Each locomotive also has an independent pneumatic brake system controlled by the operator to apply or release the locomotive brakes. The independent pneumatic brake system, which is coupled to the air brake system, applies the locomotive brakes by increasing the pressure in the locomotive brake cylinders and releasing the locomotive brakes responsive to a decrease in the cylinder air pressure.

Finally, each locomotive is equipped with a dynamic brake system. Activation of the dynamic brakes reconfigures the locomotive's traction motors to operate as generators, with the inertia of the locomotive wheels supplying rotational energy to turn the generator rotor winding. Magnetic forces, developed by generator action, resist wheel rotation and thus create wheel-braking forces. The enemy produced by the generator is dissipated as heat in a resistor grid in the locomotive and removed by one or more cooling blowers. Use of the dynamic brakes is indicated to slow the train when application of the locomotive independent brakes and/or the railcar air brakes may cause the locomotive or railcar wheels to overheat or when prolonged use may cause excessive wheel wear. For example, the dynamic brakes may be applied when the train is traversing a prolonged downgrade.

A train configured for distributed power (DP) operation has a lead locomotive at a head-end of the train, and one or more remote locomotives between the head-end and an end of the train. A DP train may also include one or more locomotives at the end of the train. The DP system further includes a distributed power train control and communications system with a communications channel (e.g., a radio frequency (RE) or a wire-based communications channel) linking the lead and remote locomotives. Though DP operation is disclosed specific to trains, similar systems are also applicable for other powered systems disclosed herein.

The DP system generates traction and brake commands responsive to operator-initiated (e.g., the operator in the lead locomotive) control of a lead locomotive traction controller (or throttle handle) or a lead locomotive brake controller (responsive to operation of an air brake handle, a dynamic brake handle or an independent brake handle). These traction or brake commands are transmitted to the remote locomotives over the DP communications channel. The receiving remote locomotives respond to the traction or brake (apply and release) commands to apply tractive effort or to apply/release the brakes and farther advise the lead locomotive that the command was received and executed. For example, when the lead locomotive operator operates the lead-locomotive throttle controller to apply tractive effort at the lead locomotive, according to a selected throttle notch number, the DP system issues commands to each remote locomotive to apply the same tractive effort (e.g., the same notch number). Each remote locomotive replies to acknowledge execution of the command.

In certain DP systems, a plurality of pressure transducers are used in an equalizing/control reservoir, brake pipe, brake cylinder, etc. at the lead locomotive and at each remote locomotives to sense when the lead locomotive makes a brake application and allows each remote locomotive to make a similar brake application. This allows for uniform braking to take place, which in turn keeps in-train forces at acceptable limits.

FIG. 1 schematically illustrates an example distributed power train 10, traveling in a direction indicated by an arrowhead 11. A remote locomotive 12A (also referred to as a remote unit) is controlled by messages transmitted from either a lead locomotive 14 (also referred to as a lead locomotive) or from a control tower 16. Control tower commands are issued by a tower operator or dispatcher either directly to the remote locomotive 12A or to the remote locomotive 12A via the lead locomotive 14.

A trailing locomotive 13 coupled to the lead locomotive 14, forming a consist, is controlled by the lead locomotive 14 via control signals carried on an MU (multiple locomotive) line 17 connecting the two units. Also, a trailing remote locomotive 12B coupled to the remote locomotive 12A, forming another consist, is controlled by the remote locomotive 12A via control signals carried on the MU line 17.

Each of the locomotives 14 and 12A and the control tower 16 includes a DP transceiver 28L, 28R, 28T (also referred to as a DP radio) and a DP antenna 29 for receiving and transmitting the DP communication messages. The DP transceivers are referred to by suffixed reference numerals 28L, 28R and 28T indicating location in the lead locomotive, remote locomotive, and the control tower, respectively.

The DP commands are typically generated in a lead station 30L in the lead unit 14 responsive to operator control of the motive power and braking controls in the lead locomotive 14, as described above. The remote locomotive 12A also includes a remote station 32R for processing messages from the lead locomotive 14 and for issuing reply messages and commands.

The distributed power train 10 further comprises a plurality of railcars 20 interposed between the locomotives illustrated in FIG. 1 and connected to a brake pipe 22. The railcars 20 are provided with an air brake system (certain components of which are not shown in FIG. 1) that applies the railcar air brakes in response to a pressure drop in the brake pipe 22 and releases the air brakes in response to a pressure increase in the brake pipe 22. The brake pipe 22 runs the length of the train for conveying the air pressure changes specified by air brake controllers 24 in the locomotives 14 and 12A. A plurality of transducers 69 is provided. The plurality of transducers 69 are associated with the equalizing/control reservoir, brake pipe, and brake cylinder at each brake controller 24 at each lead and remote locomotive. The transducers 69 communicate with the lead station 30L in the lead locomotive 14 to identify the brake application that the driver is commanding at the lead locomotive. The lead station then transmits this brake application data to the remote station 32R via the DP radios 28L and 28R. The remote station 32R then commands the remote brake controllers 24 to apply brakes as commanded from the lead locomotive. The transducers 69 communicate with the remote station 32R in the remote locomotive 12A to identify that the remote locomotive 12A is making its braking application in response to the braking application made by the lead locomotive 14.

In distributed power applications, it is especially critical to have valid and accurate pressure transducer data. During times of communication interruption, if a brake application is applied at the lead locomotive, the remote locomotive cannot receive this brake command and the lead locomotive may apply brakes at the front part of the train very rapidly while the rear part of the train the brakes are being applied at a much slower rate. Such an application of brakes may result in experiencing high in-train forces, which are unacceptable during train motoring. Additionally, pressure transducers may fail at an acceptable pressure and provide a false reading to the lead locomotive, or, more specifically, a train control system. This false reading will indicate to the system that it is safe to operate in a nominal state. The false reading might allow the system to make an unacceptable action.

Therefore, owners and operators of locomotives and trains would benefit from being able to detect when a failed or stuck pressure transducer is realized where the detection ensures that the data associated with the detection is current data. Owners and operators would also benefit from having fewer working parts in the distributed power system; therefore, an additional benefit would be realized if the detection is accurate enough to reduce the number of redundant transducers currently required.

BRIEF DESCRIPTION

Embodiments of the presently described inventive subject matter relate to a method, system, and computer software code for verifying validity of a pressure reading from a transducer on a remote powered system. The system comprises a comparator subsystem configured to evaluate a pressure reading differential taken between a first transducer that is part of a braking system on a lead powered system and a second transducer that is a part of a braking system on a remote powered system, wherein the pressure reading differential is taken when the lead powered system and the remote powered system are operating in a distributed power application. (Distributed power “application” or “mode” means coordinated control of braking, power/traction, and/or other operations as between two or more linked powered systems, e.g., the lead and remote powered systems.)

The method comprises comparing pressure measured at a first transducer to pressure measured at a second transducer to determine whether the second transducer functions properly when the powered system is operating in a distributed power mode.

The computer software code is stored on a computer readable media and is executable with a processor. The computer software code comprises a computer software module for comparing pressure measured at a first transducer to pressure measured at a second transducer to determine whether the second transducer functions properly when the powered system is operating in a distributed power mode.

A method for verifying operation of a pressure transducer comprises obtaining a first pressure reading from a first transducer in a first rail vehicle, wherein the first pressure reading relates to a braking pressure in the first rail vehicle. The method further comprises obtaining a second pressure reading from a second transducer in a second rail vehicle, wherein the second pressure reading relates to a braking pressure in the second rail vehicle, and wherein the first and second pressure readings are taken when the first and second rail vehicles are operating in a distributed power application, said first and second rail vehicles being indirectly or directly linked together as part of a series of linked rail vehicles. The method also comprises carrying out a comparison of the first pressure reading to the second pressure reading, and determining whether the second transducer is functioning within designated operational parameters based on the comparison.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the inventive subject matter briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the inventive subject matter and are not therefore to be considered to be limiting of its scope, the embodiments of the inventive subject matter will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 illustrates a prior art representation of a distributed power train;

FIG. 2 depicts a flowchart illustrating an example method for verifying validity of a pressure reading from a transducer on a remote powered system in a distributed power powered system;

FIG. 3 depicts another flowchart illustrating an example method for verifying validity of a pressure reading from a transducer on a remote powered system in a distributed power powered system;

FIG. 4 illustrates, in block diagram form, elements for reporting and acting on a fault message; and

FIG. 5 depicts a flowchart illustrating an example method for verifying operation of a pressure transducer.

DETAILED DESCRIPTION

Reference will be made below in detail to example embodiments of the inventive subject matter, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals used throughout the drawings refer to the same or like parts. As disclosed below, multiple versions of a same element may be disclosed. Likewise, with respect to other elements, a singular version is disclosed. Neither multiple versions disclosed nor a singular version disclosed shall be considered limiting. Specifically, although multiple versions are disclosed, a singular version may be utilized. Likewise, where a singular version is disclosed, multiple versions may be utilized.

Though example embodiments of the presently described inventive subject matter are described with respect to rail vehicles, or railway transportation systems, specifically trains and locomotives, example embodiments of the inventive subject matter are also applicable for use with other powered systems, such as but not limited to marine vessels, stationary units such as power plants, off-highway vehicles, agricultural vehicles, and/or transportation vehicles, each which may use at least one engine. Towards this end, when discussing a specified mission, this includes a task or requirement to be performed by the powered system. Therefore, with respect to a railway vehicle, marine vessel, agricultural vehicle, transportation vehicle, or off-highway vehicle applications, this may refer to the movement of a collective powered system (where more than one individual powered system is provided) from a present location to a destination. In the case of stationary applications, such as but not limited to a stationary power generating station or network of power generating stations, a specified mission may refer to an amount of wattage (e.g., MW/hr) or other parameter or requirement to be satisfied by the powered system.

Though diesel powered systems are readily recognized when discussing trains or locomotives, one or more embodiments of the inventive subject matter may also be utilized with non-diesel powered systems, such as but not limited to natural gas powered systems, bio-diesel powered systems, etc. Furthermore, the individual powered system may include multiple engines, other power sources, and/or additional power sources, such as, but not limited to, battery sources, voltage sources (such as but not limited to capacitors), chemical sources, pressure based sources (such as but not limited to spring and/or hydraulic expansion), electrical current sources (such as but not limited to inductors), inertial sources (such as but not limited to flywheel devices), gravitational-based power sources, and/or thermal-based power sources. Additionally, the power source may be external, such as, but not limited to, an electrically powered system, such as a locomotive or train, where power is sourced externally from overhead catenary wire, a third rail, and/or magnetic levitation coils.

Example embodiments of the inventive subject matter solve problems in the art by providing a method, system, and computer implemented method, such as a computer software code or computer readable media, for verifying validity of a pressure reading from a transducer on a remote powered system. With respect to locomotives, example embodiments of the presently described inventive subject matter are operable when the locomotive consist is in distributed power operations. Distributed power operations, however, are not only applicable to locomotives or trains. The other powered systems disclosed herein may also operate in a distributed power configuration.

In this document the term “locomotive consist” is used. As used herein, a locomotive consist may be described as having one or more locomotives in succession, connected together so as to provide motoring and/or braking capability. The locomotives are connected together where no train cars are in between the locomotives. The train can have more than one locomotive consists in its composition. Specifically, there can be a lead consist and one or more remote consists, such as midway in the line of cars and another remote consist at the end of the train. Each locomotive consist may have a first locomotive and trail locomotive(s). Though a first locomotive is usually viewed as the lead locomotive, the first locomotive in a multi-locomotive consist may be physically located in a physically trailing position.

Though a locomotive consist is usually viewed as involving successive locomotives, a consist group of locomotives may also be recognized as a consist even when one or more rail cars separate the locomotives, such as when the locomotive consist is configured for distributed power operation, wherein throttle and braking commands are relayed from the lead locomotive to the remote trains by a radio link or physical cable. Towards this end, the term locomotive consist should not be considered a limiting factor when discussing multiple locomotives within the same train.

As disclosed herein, the idea of a consist may also be applicable when referring to other types of powered systems including, but not limited to, marine vessels, off-highway vehicles, agricultural vehicles, and/or stationary power plants, that operate together so as to provide motoring, power generation, and/or braking capability. Therefore, even though the term locomotive consist is used herein in regards to certain illustrative embodiments, this term may also apply to other powered systems. Similarly, sub-consists may exist. For example, the powered system may have more than one power generating unit. For example, a power plant may have more than one diesel electric power unit where optimization may be at the sub-consist level. Likewise, a locomotive may have more than one diesel power unit. Furthermore though the examples are disclosed with respect to a rail vehicle, such disclosures are not to be considered limiting. The example embodiments are also applicable to the other powered systems disclosed herein.

An apparatus, such as a data processing system, including a CPU, memory, I/O, program storage, a connecting bus, and other appropriate components, could be programmed or otherwise designed to facilitate the practice of the method of the inventive subject matter. Such a system would include appropriate program means for executing the method of the inventive subject matter.

Also, an article of manufacture, such as a pre-recorded disk, computer readable media, or other similar computer program product, for use with a data processing system, could include a storage medium and program means recorded thereon for directing the data processing system to facilitate the practice of the method of the inventive subject matter. Such apparatus and articles of manufacture also fall within the spirit and scope of the inventive subject matter.

Broadly speaking, a technical effect is to verify validity of a pressure reading from a transducer on a remote powered system. To facilitate an understanding of the example embodiments of the inventive subject matter, it is described hereinafter with reference to specific implementations thereof. Example embodiments of the inventive subject matter may be described in the general context of computer-executable instructions, such as program modules, being executed by any device, such as but not limited to a computer, designed to accept data, perform prescribed mathematical and/or logical operations usually at high speed, where results of such operations may or may not be displayed. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. For example, the software programs that underlie example embodiments of the inventive subject matter can be coded in different programming languages, for use with different devices, or platforms. In the description that follows, examples of the inventive subject matter may be described in the context of a web portal that employs a web browser. It will be appreciated, however, that the principles that underlie example embodiments of the inventive subject matter can be implemented with other types of computer software technologies as well.

Moreover, example embodiments of the inventive subject matter may be practiced with other computer system configurations, including multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. Example embodiments of the inventive subject matter may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through at least one communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

Referring now to the drawings, embodiments of the presently described inventive subject matter will be described. Example embodiments of the inventive subject matter can be implemented in numerous ways, including as a system (including a computer processing system), a method (including a computerized method), an apparatus, a computer readable medium, a computer program product, a graphical user interface, including a web portal, or a data structure tangibly fixed in a computer readable memory. Several embodiments of the inventive subject matter are discussed below.

FIG. 2 depicts a flowchart illustrating a method for verifying validity of a pressure reading from a transducer on a remote powered system in a distributed power powered system, the distributed power powered system including the remote powered system and a lead powered system. The method in the flowchart 40 comprises measuring pressure at a first transducer on the lead powered system when a distributed braking command is applied on the lead powered system, at 42. The method continues, at 44, with applying the distributed braking command on the remote powered system. Pressure is measured at a second transducer on the remote powered system, at 46. The pressure measured at the first transducer is compared to the pressure measured at the second transducer to determine whether the second transducer functions properly, at 48. Comparing the pressure measured, at 48, may further comprise comparing the pressure measured based on a proportional difference and/or a direct difference over a nominal period of time. The compared measured pressures are communicated to a control system of the powered system, at 50. When the pressure measured from the second transducer is outside of a designated acceptable range when compared to the pressure measured from the first transducer, a failure is reported, at 52. In one embodiment, the proportional difference is an integral of a pressure difference over a time period, used to create a threshold, whereas the direct difference is an absolute difference between any two discrete periods of time which are used to create the same, or nearly equivalent, threshold. The proportional difference and/or the direct difference may be used in a calculation for analyzing, or determining, air flow. Further information about analysis of air flow may be found in U.S. Pat. No. 6,375,276 or U.S. Pat. No. 4,553,723, both herein incorporated by reference.

FIG. 3 depicts a flowchart illustrating a method for verifying validity of a pressure reading from a transducer on a remote powered system in a distributed power powered system. The method in the flowchart 60 comprises comparing pressure measured at a first transducer that is part of a braking system on a lead powered system to pressure measured at a second transducer that is part of a braking system on a remote powered system to determine whether the second transducer functions properly when the distributed power powered system is operating in a distributed power mode, at 62. Comparing the pressure measured, at 62, further comprises comparing the pressure measured based on a proportional difference and/or a direct difference over a nominal period of time. The method further comprises communicating the compared measured pressures to a control system of the distributed power powered system, at 64. When the pressure measured from the second transducer is outside of an acceptable range when compared to the pressure measured from the first transducer, a failure is reported, at 66. The method further includes obtaining a pressure reading at the first transducer, that is part of the braking system on the lead powered system, and at the second transducer, that is part of the braking system on the remote powered system, when a distributed braking command is applied first on the lead powered system and is then relayed to the remote powered system, at 68.

The methods shown in flowcharts 40, 60 may be performed with a computer software code having computer software modules where the computer software code is stored on computer media and is executed with a processor. Thus each process flow in the flowcharts 40, 60 may be performed by a computer software module specific to the process contained, in a specific process. For example, comparing pressure measured at a first transducer to pressure measured at a second transducer to determine whether the second transducer functions properly when the powered system is operating in a distributed, power mode, at 62, may be performed with a computer software module for comparing pressure measured at a first transducer to pressure measured at a second transducer to determine whether the second transducer functions properly when the powered system is operating in a distributed power mode.

A processor 71 disclosed to implement the methods and as disclosed in FIG. 4 below may not be a generic computer. Specifically, the processor 71 is unique to operate within an environment that it is exposed to when part of the powered system. Therefore a processor aboard the locomotive is not only specific to perform the methods disclosed above, but it is also able to withstand the environmental conditions experienced aboard the locomotive.

FIG. 4 depicts an example embodiment of a system for verifying validity of a pressure reading from a transducer on a remote powered system. For illustration purposes, FIG. 4 uses a train having a lead and remote locomotive. However, as disclosed above, this embodiment is application to a plurality of other powered systems operating together. The system comprises a comparator subsystem 70 located in the remote locomotive 12A, configured to evaluate a pressure reading differential taken between a first transducer 72 that is part of a braking system on a lead locomotive 14 and a second transducer 74 that is a part of a braking system on a remote locomotive 12A. The pressure reading differential is taken when the lead locomotive 14 and the remote locomotive 12A are operating in a distributed power application. The first transducer 72 pressure value is transmitted over a radio communication link established between the DP radio 28L at the lead and 28R at the remote. An operator 5 is also illustrated as being aboard the lead locomotive 14.

The comparator subsystem 70 comprises the processor 71 to compare a pressure reading from the first transducer 72 to a pressure reading from the second transducer 74. The pressure reading differential may be based on a proportional difference and/or a direct difference over a nominal period of time. The system further comprising a communication network 76 for reporting pressure data from the first transducer 72 to the brake system on the lead loco 14 and the second transducer 74 to the brake system on the remote loco 12A. More specifically, the pressure data from the second transducer 74 reports pressure data to the comparator subsystem 70 via the communication network 76. The comparator subsystem 70 and processor 71 may be integrated with the remote station 30R. The first transducer reports pressure data through the communication network 76 to the lead brake system 30L where it is then transmitted over the radio communication link to the remote locomotive 12A where it is reported to the comparator subsystem 70. The comparator subsystem 70 is also in communication with a control system 78 of the remote locomotive wherein pressure reading differential information is communicated to the control system 78. The control system 78 may also be integral with the remote station 30R.

In an example embodiment, a control-area network (“CAN”) bus may be utilized for communicating between the various elements in FIG. 4 that are on a specific locomotive. The DP radios 28L, 28R are provided to communicate between the locomotives. Using the CAN bus should result in actuate signals being transmitted and received at a high degree of integrity. Because of this integrity, a single transducer 74 may be used on the remote locomotive 12A.

In another example embodiment, where a train has a lead consist and a trail consist, instead of having a transducer only on the lead locomotive in each consist, a transducer is included on each locomotive in each consist. Within each consist, the pressure data can be compared across each consist locomotive. In another embodiment the pressure data across each consist can then be compared to the other consist. For example, after data from each locomotive in a trial consist is compared, the collective consist data may be compared to the consist pressure data from the lead consist. The lead locomotive and remote locomotive can be part of the same consist and/or may be part of separate consists.

Another embodiment relates to a method for verifying operation of a pressure transducer, as illustrated in FIG. 5. A flowchart 80 illustrates the method comprises obtaining a first pressure reading from a first transducer in a first rail vehicle, at 82. The first pressure reading relates to a braking pressure in the first rail vehicle. The method further comprises obtaining a second pressure reading from a second transducer in a second rail vehicle, at 84. The second pressure reading relates to a braking pressure in the second rail vehicle. The first and second pressure readings are taken when the first and second rail vehicles are operating in a distributed power application. The first and second rail vehicles are indirectly or directly linked together as part of a series of linked rail vehicles. The method further comprises carrying out a comparison of the first pressure reading to the second pressure reading, at 86, and determining whether the second transducer is functioning within designated operational parameters based on the comparison, at 88. (“Operational parameter” refers to an aspect or characteristic of the transducer in operation. “Designated” operational parameter refers to a particular value (or range of values) for each operational parameter that reflects a particular operational condition, such as nominal or proper operation.)

While the inventive subject matter has been described with reference to various example embodiments, it will be understood by one of ordinary skill in the art that various changes, omissions and/or additions may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the inventive subject matter. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the inventive subject matter without departing from the scope thereof. Therefore, it is intended that the inventive subject matter not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this inventive subject matter, but that the inventive subject matter will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. 

1. A method comprising: comparing a first brake pressure measured at a first transducer that is part of a braking system on a lead powered unit of a distributed power (DP) system to a second brake pressure measured at a second transducer that is part of a braking system on a remote powered unit of the DP system; and determining whether the second transducer is functioning within designated operational parameters when the DP system is operating in a DP mode based on comparing the first brake pressure to the second brake pressure.
 2. The method according to claim 1, further comprising communicating the first and second brake pressures measured at the respective first and second transducers to a control system.
 3. The method according to claim 1, wherein determining whether the second transducer is functioning within designated operational parameters is determined based on at least one of (a) a proportional difference between the first brake pressure measured at the first transducer and the second brake pressure measured at the second transducer or (b) a direct difference between the first brake pressure measured at the first transducer and the second brake pressure measured at the second transducer.
 4. The method according to claim 1, further comprising reporting a failure when the second brake pressure measured at the second transducer is outside of a designated range that is based on the first brake pressure measured at the first transducer.
 5. The method according to claim 1, further comprising obtaining the first brake pressure reading at the first transducer and the second brake pressure reading at the second transducer when a distributed braking command is first applied on the lead powered unit and is subsequently communicated to the remote powered unit.
 6. The method according to claim 1, wherein the lead powered unit and the remote powered unit respectively comprise first and second linked-together vehicles that are one or more of an off-highway vehicle, an agricultural vehicle, a mass transit transportation vehicle, a mass cargo transportation vehicle, a marine vessel, or a rail vehicle.
 7. The method according to claim 1, wherein the lead and remote powered units are at least one of a part of a consist within a series of linked powered units or are in separate consists within the series of linked powered units.
 8. A method comprising: receiving a first brake pressure reading from a first transducer that is part of a braking system of a first powered unit of a distributed power (DP) system; receiving a second brake pressure reading from a second transducer that is part of a braking system of a second powered unit of the DP system, wherein the second powered unit is remote from the first powered unit; determining a difference between the first brake pressure reading and the second brake pressure reading; and determining that the second brake pressure reading is invalid based on the difference between the first and second brake pressure readings.
 9. The method of claim 8, wherein the difference in the first and second brake pressure readings includes at least one of (a) a proportional difference between the first brake pressure reading and the second brake pressure reading or (b) a direct difference between the first brake pressure reading and the second brake pressure reading.
 10. The method of claim 8, wherein determining the difference between the first and second brake pressure readings includes comparing the first and second brake pressure readings.
 11. The method of claim 8, further comprising controlling the DP system in a manner that disregards the second brake pressure reading when the second brake pressure reading is invalid.
 12. The method of claim 8, wherein the first powered unit and the second powered unit respectively comprise first and second linked-together vehicles that are one or more of an off-highway vehicle, an agricultural vehicle, a mass transit transportation vehicle, a mass cargo transportation vehicle, a marine vessel, or a rail vehicle.
 13. The method of claim 8, wherein the first powered unit and the second powered unit are at least one of a part of a consist within a series of linked powered units or are in separate consists within the series of linked powered units.
 14. The method of claim 8, wherein the DP system is a rail vehicle system comprising a series of linked rail vehicles, the first and second powered units being first and second rail vehicles, respectively, that are directly or indirectly linked together in the rail vehicle system.
 15. The method of claim 8, wherein the second brake pressure reading is determined to be invalid when the second brake pressure reading is outside of a designated range based on the first brake pressure reading.
 16. The method of claim 8, further comprising communicating a failure report when the second brake pressure reading is invalid.
 17. A method comprising: receiving a first brake pressure reading from a first transducer that is part of a braking system of a first powered unit; receiving a second brake pressure reading from a second transducer that is part of a braking system of a second powered unit, wherein the first and second powered units are operating in a distributed power application of a distributed power (DP) system in which the second powered unit is remote from the first powered unit; and determining that the second brake pressure reading is invalid when the second brake pressure reading is outside of a predetermined operational parameter that is based on the first brake pressure reading.
 18. The method of claim 18, wherein the second brake pressure reading is not used to control braking or traction operations of the DP system when the second brake pressure reading is invalid.
 19. The method of claim 18, wherein the DP system is a rail vehicle system comprising a series of linked rail vehicles, the first and second powered units being first and second rail vehicles, respectively, that are directly or indirectly linked together in the rail vehicle system.
 20. The method of claim 18, further comprising controlling the DP system in a manner that disregards the second brake pressure reading when the second brake pressure reading is invalid. 